A plunged into the Hudson River on Thursday, turning a family outing above Manhattan’s misty skyline into a tragedy.

The helicopter carried six people, including three children and their parents – who have both worked for Siemens, a German multinational technology conglomerate. It lifted off from a Manhattan heliport and followed a familiar route: circling the Statue of Liberty, gliding north along the Hudson toward the George Washington Bridge and then turning south. About 16 minutes after takeoff, the aircraft crashed into the water, according to analysis by CNN and FlightRadar24.

Witnesses described the helicopter flipping and spiraling before crashing near the New Jersey shoreline upside down, scattering debris across the river.

“The helicopter was a little bit like nose down, slightly, and I saw the propeller separating from the helicopter. It kept spinning in the air alone. Nothing was attached to it,” Sarah Jane Raymond Ryer, who saw the crash unfold, told .

A video obtained by CNN shows the rotor blades detached from the helicopter and flying through the air. “The videotape in this case is very dramatic and very important to the investigation,” former National Transportation Safety Board managing director Peter Goelz told CNN on Friday.

Eyewitness Avi Rakesh told CNN’s Jessica Dean that what was left of the helicopter appeared to be so out of control, he didn’t feel safe in his own building.

Here’s what we know about the crash that killed everyone on board:

A Siemens family and pilot among the victims

The victims include Agustín Escobar, 49, his wife, Mercè Camprubí Montal, and their three children. New York City Mayor Eric Adams said the family was visiting from Spain, and Jersey City Mayor Steven Fulop said in a that the family was in New York to celebrate Camprubí’s 40th birthday.

“We are deeply saddened by the tragic helicopter crash in which Agustin Escobar and his family lost their lives. Our heartfelt condolences go out to all their loved ones,” a Siemens Mobility spokesperson said in a statement to CNN.

Escobar served as CEO of Rail Infrastructure at Siemens Mobility, the transportation solutions division of Siemens AG.

Spain’s Prime Minister, Pedro Sánchez, expressed his condolences, calling the incident “an unimaginable tragedy.”

“We are deeply saddened and shocked by the loss of a colleague due to a tragic accident during vacation,” said a statement from Siemens Energy. “Our thoughts and heartfelt condolences go out to the family, friends and colleagues of the victims.”

The pilot was also killed, though officials have not yet released their identity.

CNN has reached out to the New York Police Department and the US Coast Guard for more information on the victims.

Agustín Escobar, a Siemens executive, and his family were killed in a helicopter crash in New York on Thursday.

What happened

The cause of the crash remains unclear, but its sudden descent stunned witnesses as first responders raced to rescue the victims.

The helicopter took off at 2:59 p.m. from Manhattan’s downtown heliport following a popular sightseeing route, New York Police Department Commissioner Jessica Tisch said. After circling the Statue of Liberty, it flew north along the Hudson River, reaching the George Washington Bridge by 3:08 p.m. It then turned south along the New Jersey shoreline, where it lost control shortly after, Tisch said.

Visibility at the time was 10 miles, though the region was cloudy with winds of 10 to 15 mph and gusts up to 25 mph. A weather system was expected to bring light rain later in the afternoon.

At 3:17 p.m., multiple 911 calls reported a crash near Pier A Park in Hoboken, New Jersey. Witnesses said the helicopter appeared to stop midair before pieces broke off, consistent with preliminary emergency reports, Tisch said.

Jersey City resident, Ipsitaa Banigrhi, described the sound as “such a loud sound. It felt like thunder,” she told WCBS. “Then I saw black particles flying. Again, I thought maybe it’s just dust or birds, and then we heard all the emergency vehicles and sirens go by. I think that’s when it was like, ‘OK, what’s happening.’”

With the helicopter’s catastrophic failure in midair, there was no way to guide the aircraft to safety, a former combat pilot told CNN’s Kate Bolduan.

“There’s nothing that pilot could have done in that situation to recover the aircraft,” Brandt Anderson said.

First responders from NYPD and New York City Fire Department teams pulled six people from the water. Four victims were pronounced dead at the scene, and two others succumbed to injuries shortly after, Tisch said. Two children were taken to Jersey City Medical Center, where they were later pronounced dead, Jersey City Mayor Steven Fulop .

The aircraft’s main fuselage was retrieved from the river on Thursday evening, and dive operations continued Friday, WCBS reported.

Previous safety incidents

The company operating the helicopter was previously involved in two safety incidents investigated by federal aviation authorities.

In 2015, a pilot for the New York Helicopter Charter company was forced to land in New Jersey after hovering 20 feet in the air for a short time. An initial inspection showed there “may have been corrosion removed” from sections of the helicopter and that some of the helicopter’s component parts may have been deformed to an extent to be “considered unairworthy,” according to an FAA inspector at the time. The same helicopter was previously involved in a crash in Chile in 2010.

In 2013, a pilot for the company was forced to land a helicopter carrying four passengers on the water near Manhattan after hearing a “bang” that was followed by the “Engine Out warning horn.” The pilot inflated the helicopter’s floats and got the passengers to safety on a boat.

“The only thing I can tell you is that we are devastated,” Michael Roth, the CEO of the company operating the flight, told CNN of Thursday’s crash. “I’m a father, a grandfather and my wife hasn’t stopped crying since this afternoon.”

When asked about the helicopter’s maintenance, he said, “That’s something my director of maintenance handles.” The director of maintenance declined to comment.

Maintenance records are not publicly accessible, and the NTSB restricts can disclose during an ongoing investigation.

As seen from Pier 40 in New York, police and fire crews from New York and New Jersey respond to the scene Thursday.